Benchmark: Array.prototype.slice vs spread operator copy performance

Tests:

Array.prototype.slice
var params = [ "hello", true, 7 ]; var other = params.slice();
spread operator
var params = [ "hello", true, 7 ] var other = [ ...params ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.slice
spread operator

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 23 days ago):

LLMs can make mistakes. Check important info.

Measuring performance differences between programming approaches is crucial in ensuring efficient and scalable software development.

**Benchmark Overview**

The provided benchmark compares the performance of two approaches to create a copy of an array: the traditional `Array.prototype.slice()` method and the new ES6 spread operator (`[...array]`). This comparison aims to determine which approach is faster, more efficient, and suitable for various use cases.

**Options Compared**

Two options are compared:

1.  **Traditional Approach: Array.prototype.slice()**
    *   This method creates a shallow copy of an array.
    *   It's a widely supported method that has been part of the JavaScript language since its inception.
2.  **New ES6 Spread Operator: [...array]**
    *   This method creates a new array by spreading the elements of an existing array.
    *   Introduced in ECMAScript 2015 (ES6), it provides a concise and expressive way to create copies.

**Pros and Cons**

### Array.prototype.slice()

Pros:

*   **Wide support**: This method has been part of JavaScript for a long time, ensuring broad compatibility across different browsers and environments.
*   **Well-understood behavior**: The `slice()` method is well-documented and easy to use, making it a familiar choice for many developers.

Cons:

*   **Performance overhead**: Creating an array copy using the spread operator can be faster than the traditional `slice()` method.
*   **Less concise syntax**: The spread operator requires parentheses and a comma-separated list of elements, which can make the code slightly less readable.

### New ES6 Spread Operator

Pros:

*   **Concise syntax**: The spread operator allows for a more compact representation of array copying.
*   **Performance benefits**: In some cases, it might outperform traditional methods like `slice()`.
*   **Modern feel**: Using the spread operator can give code a more modern and idiomatic look.

Cons:

*   **Newer method**: While widely supported, this method is still relatively new compared to `slice()`.
*   **Potential inconsistencies**: Some older browsers or environments might not support the spread operator.

**Library Usage**

Neither of the two methods explicitly uses any libraries. They are part of the JavaScript language itself.

**Special JS Features/Syntax**

The benchmark does not test special JavaScript features or syntax beyond the use of the ES6 spread operator and `Array.prototype.slice()`.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36

Browser/OS: Chrome 103 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.slice	69714632.0 Ops/sec
spread operator	43728364.0 Ops/sec

Related benchmarks:

Array.prototype.slice vs spread operator copy performance (version: 0)

Compare the new ES6 spread operator with the traditional slice() method

Comparing performance of: Array.prototype.slice vs spread operator

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.slice

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 23 days ago):